1. Field of the Invention
The present invention relates to a video mixing apparatus for mixing a playback video signal obtained by playing a recording medium and a graphics video signal obtained based on a data processing.
2. Description of Background Information
An apparatus for mixing a playback video signal indicative of a moving image or a still image, obtained by playing a recording medium such as a video disk or the like, and a graphics video signal indicative of a graphics video image based on graphics data obtained as a subcode signal. Such apparatus are disclosed, for example, in Japanese Patent Application Kokai No. 1-256071. In the video mixing apparatus disclosed in this document, the playback video signal and the graphics video signal are adjusted individually through a variable resistor and added together. Resistance values of the variable resistors are manually changed so that a mixing ratio of the playback video signal and the graphics video signal is arbitrarily determined.
In such a conventional video mixing apparatus, however, a graphics video image and a playback video image are mixed at the same mixing ratio on one screen. That is, the above apparatus is not designed so that a part of one image plane of a graphics video image and the other portion thereof can be mixed at different mixing ratios into a playback video image or so that a part of one image plane of a playback video image and the other portion thereof can be mixed at different mixing ratios into a graphics video image. This means that in a television game apparatus using a graphics video image, it is impossible to form several video images by mixing a graphics video image of every video image such as background, person, characters, or the like, and a playback video image.